Process and apfabatus fob dbawing sheet-glass



I. H. KENDIG.

PROCESS AND APPARATUS FOR DRAWING SHEET GLASS.

APPLICATION FILED IULY I9,\I9I6.

APatented June` 3, 1919.

I1 II ,II I :I III III..

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O vv All.

ATTORNEYS.

WITNESSZ f rnocnssv AND -Arrnna'rus non rnanwrnel SHEET-GLASS."

Be` it known that. I, J ULIA To 'alli/whom z'tmay 'concern I-I, KENDIG,

, a -citizen 'of lthe United States, residing at Pittsburgh, inI the county of Allegheny and State of Pennsylvania,V have invented certain new and useful Improvements in -Proc esses and Apparatus for Drawing Sheet- Glass, of which the' following is a specifica.- tion. l i

This invention relates to a process and ape paratus for drawing sheet glass, and has for its principal objects the provision of aprocess and apparatuswhereby glass may be taining a body of mo continuously drawn from a tank in the form i of a flat sheet; the provision of an appa` ratus whereby the glass is supported while being drawn for the purpose of maintaining the glass in the form of a flat sheet, without marring the surface thereof; the provision of a machine that will form at a'minimum of cost, sheet glass, free ofjblemishes and uniform in thickness, and such other objects as may hereinafter appear. One em? bodiment of the invention is illustrated in the accompanying drawings, wherein*- Figure 1 isa side elevation of the apparatus showing the tank and leer in section; and Fig. 2 is a section on the line II-II of Fig. 1.

The apparatus comprises a tank l conten glass 2 which `is maintained at a constant level by any convenient means.

The delivery end of the tank is openat its front end to permit glass to How over the top edge of the front Wall 3 while the apparatus is in operation. A (gate 4 is provided to extend across the en of the tank for the purpose of closing the discharge opening when the apparatus is not in operat1on. When the apparatus is in operation the gate 4 is held beneath the surface of the lass by any convenient means, and when 1t is desired to shut off the ow of glass tne gate 4 is elevated so that the 'to edge thereof projects above the surface o the glass.

A skimmer 5 extends from one side of the tank to the other and is for the purose of preventing the impure surface glass Ifrom flowin out of the tank. The glass passing to `t e drawin must come from beneat t e surface where the purest lass is obtained.

A cylin rical supporting roll 6 is posi# tioned adjacentl the end wall 3 so that the axis thereof is approximately on the same Animanga mea my is, 191,6, sensi. in 110,096.,

o ening v therefore specimen@ of ieftesrafm- Patented June 3,1919- levelmals'the glass'in the tank, and so that the surface, ofthe roll almost touches the top outside corner 7. of the end wall. The

roll consists of a supporting rim or cylinder 8 carried by the spokes 9 and is provided with a bearing shaft 10 extending through the center thereof and projecting beyond the ends'of the roll. Upon the rim or cylinder 8 is mounted a series of planks 11 made preferably of bass wood, or a composition of bass wood sawdust and molasses, which has been baked in molds. Any substance that is non-heat conducting and will not scratch or score the glass mi ht be substior e composition just referred to or any substance that will be carbonized with a smooth char is preferable.

The planks or blocks 11 may be secured to the rim 8 by any suitable means, and are preferabl sawed or molded with curved sides wit sides cut away to form a dee narrow groove 12 between each plank or b ook. When the planks are mounted upon the rim the grooves tuteg, but it has been found t at bass wood a portion of one of the curved 12 will be curved as shown in Fig. 2, and the Y' reason for the curved after appear. l

The roll is mounted for rotation upon movand transversely of the tank 1. The bearings 13 are slidably mounted upon bases 14 and are adapted to be movedl toward 'and grooves will hereinv 'able bearings 13 through which the ends of the shaft 10 project, and. sufficient space is away from the tank 1 by means of the screws 15 which are threaded through the bearings and supported and held against longitudinal movement b y the base. When the wheels 16 are simultaneously turned the bearings will 'l sheet of glass is placed between the drawing rolls 17 and 18 which are adapted, to be turned in either direction. The roll 6 is ro- `tated preferably anti-clockwise, so that the surface thereof above the level of'the glass moves toward the` glass. The gate 4 is then lowered permitting the molten lass to come 'incontact with the surface of t e roll Aat 19,` i

The heat of theglass will char or carbonizethe surface of the planks or blocks uniformly over the revolvin surface thereof but the blocks are burne only to a limited depth because the surface is continuously moving .and is being cooled by the surroundin air cold sheet the rolls 17 and 18 `are reversed vso sheet at the point where the that the plastic sheet will be slowly drawn up over the surface of the revolving roll 6, ilhe roll 6 is turned so that the surface thereof moves considerably fasterthan the glass being drawn over it. Therefore each. particle of the under surface of the glass is 'being continuously rubbed or stroked in a path parallel with the path of the draw and is prevented from moving toward the center of thesheet by the tendency of the roll to maintain itin a straight path parallel to the path of the draw. Because 'of this tendency of the roll to keep each particle in a straight path and because of the support that the roll adords the glass While it is vlastic; the sheet maintains its original width indefinitely. The glass adjacent the surface Will tend to cling to the side wall of the tank and will draw out slightly as at A. rI`his formation assists in maintaining the vfull width of the glass leaves the main' body of glass.

A further condition which assists in maintaining the lassl in sheet form is the contact Whichthe g ass has with the roll at 19 beneath the surface of the glass. The glass is partially cooled throughout the width of the sheet beneath the surface and therefore receives an initial hardeningin sheet form betank.

60 wise, to assist in preventing the particles of The curved grooves 12 'are provided 'to stroke the glass away from the center toward the edges when the roll is turned anti-clockglass from moving toward the center of the sheet. It is preferable turn the roll so that the surface thereof moves in the direction opposite to that in which the glass is az Lacasse being dravvn2 but the roll'may be turned in the reverse dlrection, in which event the roll should be reversed so that the curved grooves thereof will. always tend to stroke the glass away from the center. Another function of the groove Vis to conduct any gases formed by the combustion of the Wood away from the under side of the glass.

Because the surface of the roll moves at a higher velocity than the surface of the glass, the sheet is maintained at its original Width, and is at the same time polished while tinuously draw the glass sheet 26 over the roll 6 and deposit it upon an endless belt carrier 21 to be hereinafter described. l

rlhe driving rolls 17 ,and 18 and the carrier 21,- which are merely `shown diagramof tangency of the sheet 20v/With respect to the roll 6 may be shifted to suit operating conditions, but it is preferable that the glass should not leave the wheel surface until it is just ready to set \or become hard, so that the sheet is stretched straight before it finally hardens. For lin the temperature o the sheet so that it wil set or harden j after it leaves the wheel or at the point marked S, a gas burner 22 and air pipes 23 and 2e are provided. The dow of gas is regulated by the valve 25 and the air pipes 23 and 24 are controlled by valves 26 and 27, respectively. By mattpurpose' of control-- rllhe rolls 17 and 18 continue to turn in the direction of the arrows, and con- `matically, may be moved so that the point nipulation of these valves the temperature of the sheet may-be regulated and the glass kept'from .cooling abruptly. Means for absorbing the heat, such as water cooled tubes placed adjacent the surface of the glass, may be u in place of the air pipes for regulating,v the temperature of the sheet. @ne reason for preferably turning the wheel 6 so that its surface moves in a Jdirection opposits to that in which the glass is being drawn will be seen from the following.

trthat the glass is set hard above the oint S, and sufficiently set below the point S to the point C to prevent the lolnssiveaction ofthe moleculesfrom draw? the molecules toward the center of the sh, then fthespace in which there is ai tendency'for the cohesion of the molecules to 'draw them toward the center of the sheet 1s between the point C and the surface of the glass 2. A chain of molecules suspended pen ent from the point C where they cannot move toward the center of the sheet will bestrokeddownward in a straight line, by

the surface of the roll and because of the frictional engagement of the roll will be prevented from moving toward the center of the'sheet. A This action is'further assisted by the curved grooves 12 which vtend to ward about the shaft 31 by means of the .rod 33 pivoted to the lever 34 secured to the carrier frame 30. When the belt 32 assumes the position indicated by the dotted line, the gear 35 on the roll 29 will mesh w-ith the gear 36 as indicated. The gear 36is continuously rotated and will' drive the endlessv belt 32 thereby' moving the glass sheet onto the carrier 37. lThis carrier conducts the sheet through a suitable leer 38v for the purpose of permitting the lass to cool radually. After the sheet as been dellvered to the leer carrier, the frame 30is ain elevated to receive and support the vs eet being drawn. The rolls 17 and 18 and the carrler 21 may be incased in a suitably heated oven or extension of the leer to prevent sudden cooling of the glass as it is being drawn. I

The temperature of the surface of the roll is regulated by means of one or more air blasts 39 arranged beneath the roll at suitable locations, and to insure uniform wearing of the surface,.the roll is moved back and forth longitudinally quite slowly as the glass is being drawn.

It is obvious that the process may be carried out by a machine of different desi and construction and many changes may made inthe details of operation and con'- struction without departing from the spirit of the invention, and the invention is therefore not limited to the specific construction herein illustrated and described.

What I claim is: 1. The herein described-process of making sheet glass-which consists in drawing a plaslof emergence from'the body of glass to a r'emote point, in moving the supporting. surtic sheet of glass directly from the surface of a body of molten glass' upwardly, while plastic, over a smooth supporting surface that will not mar the glass, inclined from the perpendicular so as to support the glass in sheet form substantially from the point face which is in contact with the glass with respect to the glass while the glass is being drawn, and in permitting the glass to cool.

2.' The herein described process of making sheet glass which consists in drawings. plastic sheet of glass directly from the surface of a body of molten glass upwardly, while plastic, vover a carbonized su portingsurface inclined from the perpen icular So as to support the glass substantially from the point of emergence from the body of glass to a remote point, in moving the supporting surface which is inv contact with the glass with respect to the glass while the glass is being drawn, and in permitting the glass-to cool.- x

3. Tle herein described process of making sheet glass which consists in drawing a plastic sheet of glass directly from the surface of a body of molten glass 'upwardly over a .roll having a supporting surface that will not mar the glass disposed so as to support the glass in sheet form substantially from the point of emergence from the body of lthe glass to a remote point, in turning the rol-l l so that the surface thereof which is in contact with the glass has relative movement with respect to the glass while the glass is being drawn, and in permitting the glass l to cool. y

4. .The herein described process of making sheet glass which consists in drawing a plastic sheet of glass directly from the surface of'a body of molten glass upwardly, While plastic; over a roll having a carbonized supporting surface disposed so as to support the glass substantially from the point of emergence from the body of glass to a remote point, in turning the roll so that the surface thereof which is lin contact with the glass has relative movement with'respect to the glass while'the glass is being drawn, and A in permitting the glass to cool.

:N 5. The herein described process of making sheet glass which consists in drawing a plastic sheet of glass out of a body of molten glass, in supporting the sheet of plastic glass from the point Where it leaves the body of molten glass substantially to the point where.

the glass hardens, upon a smooth surface, in moving the supporting surface with respect to the glass while the glass is being drawn and in permitting the glass to cool.v

6. The herein described process of making sheet glass which consists in drawing a plastic sheet ofglass out of a body of molten glass, 1n supporting the sheet of plastic glass from the point where it leaves the body of molten glass substantially to the point ywhere the glass hardens, upon a carbonized supporting surface, in moving the supporting surface with respect to the glass while the glass is beingdrawn and in permitting the glass to cool.-

7. The herein described process of making sheet glass which. consists in drawing a plas.v

tic sheet of glass out of va body of molten glass, in supporting the sheet ofl plastic glass from the\point where it leaves the body of molten glass substantially thepointwhere the glass hardens, upon a portion thetice sheet of glass directly from the surface of a body of molten glass upwardly, while plastic, over a roll having a supporting surface ofsoft carbon disposed so as to support the glass substantially-from the point oit emergence from the body of glass to a remote point, in turning the roll `so that-the surface thereof which is in contact with the glass moves in theidirection opposite'to that in which the glass is being drawn, and in I permitting the glass to cool.'

9. rlhe herein described process of. making sheetglass which consists in drawing a plastic sheet of glass directly from the surface of a body of molten glass ,upwardly over a cylindrical roll having a surface that will not mar the glass and so disposed as to 'support the glass in sheet form substantially from the point or emergence from the body of the glass to a remote point, in turning the roll so that the surface thereof which is in contact with the glass has relative movement with respect to the glass and in permitting the glass to harden just after it leaves the curved surface ofthe roll.

l0. rlhe herein described process or" making sheet glass which consists in drawing a plastic sheet of glass directly from the surface of a body of molten glass, in drawing the sheet while plastic upwardly over a cylinder having a surface composed of a substance adapted to be vcarbonized by the heat of the glass and dis osed so as tov support the glass substantia y from the point of glass while the glass .is being drawn, and in permitting the glass to cool.

emergence from the body of the glass to a remote point, in turning the roll so as to intermittently move the particles of the surface out of contact with the glass to retard' combustion thereof, and in permitting the glass to cool. v v Y 11. The herein described process of making sheet glass which consists in drawing a plastic sheet of glass directly from thes'urface of a body of molten glass, in drawing the sheet upwardly While plastic over a smooth relatively non-heat conducting supporting surface disposed at an angle from the perpendicular so as to support the glass substantially from the point of emergence from the body o glass to a remote point, in

moving the supporting surface which is in contact with the glass with respect tothe 12. The herein 'described process' or making sheet glass which consists in draw e plastic sheetot'glass out et a body or molten recae glass, in drawing the sheet overa smooth supporting surface While plastic, in stroking the entire sheet of glass in a directionrom the center of' the sheet toward the edges thereof while plastic and in permitting the glass to cool.

13. The herein described process of malring sheet glass which consists in drawing a plastic sheet of vglass upward out of a body of molten glass,`in stroking the entire sheet tangent to the surface thereof at an angle' less than a right angle to the perpendicular, 'in supporting the glass in the plane o'tangcncy as it separates from the surface of the roll, and in permittingl the glass to harden directly after it separates from lthe roll.'

15. The herein described process of mal:-

ing sheet glass which consists in drawing a plastic sheet of glass upward out of a body of molt/en glass, in drawing the sheet over a roll having a smooth supportin surface in contact with the surface of the ody of the glass, in separating the sheet from the' roll tangent to the surface thereof at an angle less than a right angle to the perpendicular, 1n supporting the glass in the pla of tangency 'as it separates from the surface of the roll, in rinitting the glass to harden directly a ter it separates from the roll, in Severin the glass in sections while supported 1n the plane of tangency and in lowering vthe sections 'to the horizontal planeafter-it has been severed.

of glass in a direction from the center of the from the point onemergence of the sheet fromthe molten lass to a remote point, the

surface of the ro l in contact with the glass being adapted to' be moved with respect to th,l surface of ro the glass in. contact lwith. the

17. ln combination witha machine for drawing sheet glass having a tank for con-l taining molten glassand a means for drawing glass directly from the surface thereof,

- a-conti-nuously turning roll provided with a surface that will not mar the glass and disposed so as tosupport the plastic glass in sheetiorm as 1t is be drawn substantially surfacefofthe roll contact with the glass being adapted to be movedin a direction 1 opposed Ato, thedi're'ction in which the surface of the glass in'contact withthe-roll is being.'drawn.r

18. In combination with a machine for drawing sheet glasshaving .a tank for "con- .taining molten glass, and a means for drawing glass therefrom, a roll adapted-.to bc continuously rotated in contact with the surface of the molten glass for supporting the plastic glass in sheet form as 1t is bein drawnupward over the roll, provided wit a surface adapted to be carbonized by the heat of the glass in contact therewith, the said surface having relative movement with the glass in contact therewith.

19. In combination in a machinel for drawing sheet glass havingatank for containing molten lass and 'a means for drawing glass there om, a roll adapted to be continuously rotated for supporting the plastic glass in sheet form as 'it is being drawn provided with a surface having grooves on the surface thereof arran ed so that the edges of the grooves will stro e the glass from the center of the sheet toward the edges as the glass is being drawn over the surface of the roll.

u surface having curvedgrooves onL the surface theeo'f arranged so that the edges of the grooves will stroke thefglass from the l center of the sheettoward the edges as the gliss is being drawn over the surface of the ro ingl sheet glass which consists in placing a ro having asurface that will not mar the glass adjacent the discharge openinigl of a ass, in o tank containing molten wing molten glass through the 'scharge opening the surface of the roll, in drawing a s eet of. glass out of the tank upwardly over the surface of the roll above the surface of the molten glass, and in turning the roll so `that the surface thereof in contact-with the glass has relative movement withrespect to the glass in contact therewith.

22. The herein described prcceeecf mgl sheet glam which consists in placing a 10 having a surface that will not'mar the' glass adjacent the discharge opening4 of a v 2l. The herein process of maky tank containingl moltenV glass, in flowing molten glass through the discharge opening against the surface of the roll, in drawing a' sheet of glass out ofthe tank upwardly over A the surface of the roll above the surface of the-molten glass, and in turning the roll so that the-surface thereof inv contact with the glass moves in a direction opposite to the direction in which the'glfassis being drawn.

23;' machine for drawing sheetglass comprising in combination, a Ytank for containing molten glass provided with a lateral discharge opening, a roll having al surface which will not mar the glassV adjacent the discharge opening so as to engage the hori zontal surface of the glass in the tank and having a portion of its surface extending above the surface of the vglass in the tank, and means for drawing a sheet of glass from the molten glass upwardly over the roll as the roll is rotated. e y

24. A'machine for drawing sheet glassl comprising in combination, a tank for containmg'moltenglass, a support in engagement with the glass having a portion of its surface inclined at an angle to the perpendicular above the surface of the glass, means for drawing a sheet of glass upward over the y `support at an 'angle lessthan a right angle to thev perpendiculan'means for supporting the glass at the prescribed angle while being drawn, and means for lowerin the glam to a horizontal position after the eet is drawn.

25., A machine for drawing sheet glass comprisingcin combination, a tank for con-v tainingmolten glass, a roll having a surface A that will not mar the glass in engagement with the surface of the glass having a por` tion of its surface above the surface ofthe glass, means for drawing a sheet of glass upwardly over the surface of the roll and out of engagement therewith at an angle less than a right angle to theA perpendicular, means for supportmg a sheet at the prescribed angle while beingdrawn, and means for lowering the sheet to a substantially horizontal position after thev sheet lhas drawn.

26. The herein dceciiiied procese cf drewing sheet glass which consists in placing a support having a surface that will not mar the glass adjacent the discharge openingof a tank containing molten lass so that it pro- ]ects above the surface t ereof, in flowing molten glass horizontally thr h the dis'- charge opening against the sur ace of the support and in drawing a sheet of glass up- =wardly over the support to mamtain it m sheet form while plastic.

.e HelKENDIG. 

